Tank drain plug



Oct. 2, 1956 A. 'r. CORDILL TANK DRAIN PLUG Filed April 15, 1953 INVENTOR. l4 LEN ['(025 u 4,

TANK DRAIN PLUG Allen T. Cordill, Indianapolis, .Ind.

Application April 13, 1953, Serial No. 348,245

l-Claim. (Cl. 210-57) Storage tanks for fuel oil, gasoline, and other nonaqueous liquids lighter than and immiscible with water frequently accumulate water which settles to the bottom of the tank where the normal withdrawal opening is provided. To prevent contamination by the water of the stored liquid withdrawn from the tank, it is common practice to provide a tank at its lowermost point with means for withdrawing accumulated water and at a higher point with means for withdrawing the stored liquid. This application relates to a tank fitting which will provide an outlet for accumulated water and another outlet for the stored liquid.

It is an object of my invention to provide for a storage tank an outlet fitting which will provide means for effecting a controlled withdrawal of accumulated water and which will also provide means for the attachment of a pipe through which the stored contents of the tank may be withdrawn. Another object of the invention is to produce such a fitting which can be simply and economically manufactured. A further object of the invention is to provide a fitting so constructed that the means controlling the withdrawal of water will be concealed, whereby to lessen the likelihood that the tank will be emptied by unauthorized or irresponsible persons.

In carrying out the invention, I employ a cup-like fitting provided with two separated, upwardly opening wells or chambers and adapted for connection to an opening in the bottom of a storage tank. One of the wells extends to a higher level than the other, preferably to a level above the tank-bottom, and is adapted at its lower end for connection to a pipe through which the stored contents of the tank may be withdrawn. The other well is provided at its bottom with a restricted outlet controlled by a valve operable from beneath the fitting. Preferably, the bottom of the last mentioned well is formed with a frusto-conical valve-seat and, below such seat and coaxial therewith, with a screw-threaded opening receiving the screw-threaded shank of a valve member having a frusto-conical head co-operating with the seat. One or more restricted passages communicating with the interior of the valve seat extend downwardly through the bottom of the fitting to provide a path for discharge of the contents of the associated well when the valve is open.

The accompanying drawings illustrate the invention:

Fig. 1 is a top plan view of a fitting embodying my invention;

Fig. 2 is a vertical section on the line 2-2 of Fig. 1,

showing the fitting in association with the bottom of a storage tank; and

Fig. 3 is a view similar to Fig. 1 illustrating a modified form of fitting.

The drain fitting shown in Fig. 1 comprises -a cup-like body 10, conveniently a casting. The interior of the body 16 is divided by a partition 11 into two wells 12 and 13, the former of which extends upwardly beyond the open end of the latter. At its upper end, the body is threaded exteriorly for reception in a flange fitting 15 secured to a tank bottom 16 in line with an opening 17 nited States Patent 0 2,765,082 Patented Oct. 2, 1956 therein. The arrangement should be such that when the body '10 is tight within the .fla-ngefitting 1,5 :the open -upper end of the well 12 will be above and theopen upper end of the well 13 below the tank-bottom.

In line with the well 12, the bottom wall of the body 10 is provided with a screw-threaded opening 19 for the reception of a pipe or other conduit 20 through which the contents of the tank maybe withdrawn as desired. In line with the well -13 the bottom of the body 10 is provided with a frusto-conical valve seat 21 and, :in line with such valve seat, with a screw-threaded opening 22. A valve for controlling discharge from the well 13 comprises a valve member having a frusto-conical head 23 co-operating with the valve .seat21 and a screw-threaded shank 24 received in the screw-threaded opening 22. Restricted drain passages 25 opening into the face of the valve seat 21 are drilled through the bottom of the body 10.

The valve 23-24 is adapted at its lower end for the application of a tool by which the member may be rotated to open and close the valve. As shown, the lower end of the shank 24 is provided with a hexagonal recess 26 for the reception of a wrench like those used in tightening hollow-head set-screws. For purposes of assembling the fitting, a similar provision 26 may be provided in the upper face of the valve-head 23. Desirably, the valveshank 24 is short enough so that its lower end does not project below the bottom 10 when the valve is closed.

When a fitting of the type described is in use, the valve 2324 will normally be closed. Water accumulating and settling to the bottom of the tank will enter the well 13 and displace upwardly the lighter stored contents of the tank. Such accumulated water cannot enter the well 12 for withdrawal through the pipe 20 until the waterlevel rises to the upper end of the well 12. To prevent water from accumulating in the tank to a point whe e it can enter the well 12, the valve 2324 is periodically opened to drain the accumulated water through the restricted passages 25. Because such passages are of small cross-sectional area, the water emerges slowly, does not prevent ready manipulation of the valve member, and can be collected and removed in a small vessel. By observing the liquid withdrawn through the passages 25 it is possible to determine when the stored tank-contents begin to emerge, and when that occurs the valve can be closed.

The modified fitting illustrated in Fig. 3, instead of having a body formed as a unitary casting, is assembled from separate parts. It comprises a body 30 in the form of a short length of pipe or tube threaded eX-teriorly at its upper end for reception in the flange fitting at the bottom of the storage tank and closed at its lower end by a cap 31. The cap 31 is provided with a screwthreaded opening 32 corresponding to the opening 19 of Figs. 1 and 2; and in line with such opening there is secured to the cap a tube 33 which projects upwardly to a point above the upper end of the body 30. At one side of the opening 32, the cap 31 is provided with a valve seat 34 and a screw-threaded opening 35 similar to the corresponding elements of Figs. 1 and 2 and adapted to receive a valve member 36. One or more passages 37 corresponding to the passages 25 and drilled through the cap open into the face of the valve seat.

In the device of Fig. 3, the tube 33 may be held in place in the cap and the cap held in place in the body 36 by solder, brazing or other expedient which will provide liquid-tight joints. The space Within the tube 33 constitutes a well corresponding to the well 12 of Figs. 1 and 2, while the space outside such tube and Within the body 30 constitutes a second well corresponding to the well 13 of Figs. 1 and 2. The device of Fig. 3 operates as does the device of Fig. 2.

When a device embodying my invention in its preferred form is in use, the existence of the valve 23-24 or 36 is not apparent on casual inspection. This fact lessens the likelihood that children or other irresponsible persons will open the valve and drain the tank. On tanks installed out-of-doors, the inconspicuous character of the valve lessens the likelihood of theft of the tank-contents.

I claim as my invention:

A drain fitting for installation in the bottom of a liquid-storage tank, comprising a cup-like body divided interiorly into first and second wells, said first well extending above said second well and being provided at its bottom with a main outlet opening, said second well having in its bottom a screw-threaded opening the upper end of which is conically countersunk to provide a valve seat, and a valve member having a screw-threaded shank received in said opening and a frusto-conical head fitting said valve seat, said second well being provided with one or more restricted drain passages opening in said valve seat to be closed by said head, said shank being located Within the vertical limits of the bottom of the second well, the lower end of the shank having provisions for application of a valve-rotating tool.

References Cited in the file of this patent UNITED STATES PATENTS 192,145 Borden June 19, 1877 824,229 Beebe June 26, 1906 1,011,821 Lampman Dec. 12, 1911 1,106,352 Adair Aug. 4,v 1914 FOREIGN PATENTS 4,563 Great Britain Apr. 25, 1916 379,352 Germany Aug. 23, 1923 

